//2009/07/27 16:54:05
#include <algorithm>
#include <vector>
#include <string>
#include <iostream>

using namespace std;

class ProblemWriting
{
public:
    string myCheckData(string a)
    {
        if (a.size() > 25)
            return string("dotForm must contain between 1 and 25 characters, inclusive.");
        if (isdigit(a[0])==0)
            return errat(0);
        bool numnext=true;

        for (int i=0; i<a.size(); i++)
        {
            char ch = a[i];
            if (numnext && isop(ch))
                return errat(i);
            if (!numnext && isdigit(ch) != 0)
                return errat(i);
            if (!isop(ch) && !isdigit(ch) != 0 && ch!='.')
                return errat(i);
            if (isop(ch))
                numnext=true;
            if (isdigit(ch) != 0)
                numnext=false;
        }

        if (isdigit(a[a.size()-1]) == 0)
            return errat(a.size());

        return string("");
    }
private:
    bool isop(char c)
    {
        return (c=='+') || (c=='-') || (c=='*') || (c=='/');
    }
    string errat(int i)
    {
        char ch[1000];
        sprintf(ch, "dotForm is not in dot notation, check character %d.", i);
        return string(ch);
    }
};
